1. Field of the Invention
The present invention relates to a start control for a passenger protection system which can achieve protection of the passenger at the time of a vehicle crash and, more particularly, a start control for a passenger protection system which can achieve improvement in the certainty of the crash detection.
2. Description of the Related Art
As the start controlling system for the passenger protection system which is represented by the so-called air bag system, there is the start controlling system disclosed in, for example, Patent Application Publication (KOKAI) Hei 8-310339, etc.
In such start controlling system for the passenger protection system, for example, the accelerator sensor, the CPU for executing the start program, the interface circuit, etc. are incorporated in a housing as one unit which is normally called an "ECU (Electronic Control Unit)". Then, the ECU is placed at a suitable position of a vehicle via a fitting tool, i.e., a fitting bracket.
In the meanwhile, various states exist as the traveling state of the vehicle, and in some cases, so-called underfloor interference may be caused by the vibration state of the vehicle. In such case, there is a possibility that resonance of a fitting bracket for fitting the above ECU is caused. As a result, such vibration may be considered as an acceleration G which is detected by the accelerator sensor as exceeding a predetermined value and thus the passenger protection system is started.